A miniature mass analyser for in-situ elemental analysis of planetary material–performance studies

Abstract

The performance of a laser ablation mass analyser designed for in-situ exploration of the chemical composition of planetary surfaces has been investigated. The instrument measures the elemental and isotopic composition of raw solid materials with high spatial resolution. The initial studies were performed on NIST standard materials using IR laser irradiance (< 1 GW cm(-2)) at which a high temporal stability of ion formation and sufficiently low sample consumption was achieved. Measurements of highly averaged spectra could be performed with typical mass resolution of m/Δm ≈ 600 in an effective dynamic range spanning seven decades. Sensitive detection of several trace elements can be achieved at the ~ ppm level and lower. The isotopic composition is usually reproduced with 1% accuracy, implying good performance of the instrument for quantitative analysis of the isotopic fractionation effects caused by natural processes. Using the IR laser, significant elemental fractionation effects were observed for light elements and elements with a high ionization potential. Several diatomic clusters of major and minor elements could also be measured, and sometimes these interfere with the detection of trace elements at the same nominal mass. The potential of the mass analyser for application to sensitive detection of elements and their isotopes in realistic samples is exemplified by measurements of minerals. The high resolution and large dynamic range of the spectra makes detection limits of ~100 ppb possible.

Towards Structural Analysis of Polymeric Contaminants in Electrodeposited Cu films

“…To overcome these inherent limitations of the SIMS technique and to determine the actual incorporation of the suppressing complex into the final copper deposit, we made use of a truly quantitative, sensitive (10 ppb element/isotope concentration in sample material, atomic fraction) LIMS depth profiling instrument that can achieve even sub-nanometer vertical resolution [33][34][35][36][37][38]. The capabilities of this technique on the analysis of copper electrodeposits prepared with the Imep-SPS additive package were recently proven for multilayered samples that were also prepared by an oscillatory Cu electrodeposition [41].…”

“…For that purpose we conducted complementary Laser Ionization/Ablation Mass Spectrometry (LIMS) [33][34][35][36][37][38], Secondary Ion Mass Spectrometry (SIMS) and Focused Ion Beam (FIB) investigations on Imep-assisted copper electrodeposits and proved its marginal embedment into the copper matrix. Preliminary laser desorption studies performed inside layers of high additive concentration support the validity of our proposed reaction mechanism (Fig.…”

“…The counter electrode was placed inside a glass compartment separated from the main electrochemical cell by a glass frit. [33][34][35][36][37]. An ultrashort pulsed laser system (pulse width τ ∼ 190 fs, wavelength λ = 775 nm, laser pulse repetition rate ≤ 1 kHz) is used as an ablation ionization source [35].…”

“…To obtain statistically significant data, the LIMS depth-profile analysis was carried out on a analyzing the temporal evolution of the signal intensity of a selected element/isotope in the TOF spectra [34]. With the knowledge of the Cu layer thickness and number of applied laser shots the mean ablation rate per single laser shot was derived.…”

On Applicability of a Miniaturised Laser Ablation Time of Flight Mass Spectrometer for Trace Elements Measurements

“…Present laboratory efforts are focused on investigation of performance of the instrument. This report extends and follows our recent publication summarising the studies on NIST standard materials, minerals, and meteoritic samples ablated by a nanosecond IR laser radiation [27]. The choice of the IR laser is (although not generally preferred) motivated by simplicity and robustness of this laser.…”